Distillate petroleum product and method of treating the same



Patented May 15, 1934 UNITED STATES PAT DISTILLATE, PETROLEUM PRODUCTAND METHOD or TREATING THE SAME James B. Rather and Leslie 0. Beard,Jr., Brook.- lyn, and Orland M. Reiff, Jackson Heights, N. Y.,.assignors to Socony-Vacuum Corporation, New York, N. Y., a corporatibnof New York No Drawing. Original application June 25, 1930, Serial No.463,824. Divided and this application June 7, 1933, Serial No. 674,772

f3 Claims. (Cl. HP-9) This invention relates to distillate petroleumproducts, more particularlygasoline and kerosene, and .to a method ofand means for imparting a stability thereto with respect" to color, gumformation and odor, and for removing any 0b-' je'ctionable color,developed therein during storage.

This application is a division of our application Serial No. 463,824,which in turn is a continuation-in-part of our co-pendingapplicationsSerial No. 395,192, filed September 25, 1929, and Serial No. 165,546,filed February 3, 1927.

Heretofore we have discovered that certain organic compounds of thenature of negative oxidation catalysts have the property of preventingor materially delaying the formation of color, gum and malodorousconstituents in distillate petroleum products, particularly gasoline andkerosene. Notable amongst these compounds are the hydroxybenzenes,especially hydroquinone and pyrogallol. Certain of these compounds,particularly hydroquinone and pyrogallol, have the added property ofdecolorizing distillate petrowleum products which have becomediscoloredduring storage.

We have found, however, that a number ofthese compoundswill not functionproperly in the presence of water, due to the fact that they r areconsiderably more soluble in water than in the distillate petroleumproducts. This charof these compounds as stabilizers and decolorizers,particularly when the treated distillates are handled in bulk, becauseof the difiiculties involved in maintaining tankers, storage tanks, pipelines and delivery trucks free of water.

In accordance with the present invention, however, the decolorizationand/0r stabilization of distillate petroleum products with regard tocolor, gumformation and odor may be readily and effectually attainedregardless of the presence of water, by the use of certain compounds,more soluble in the distillates and less soluble in water,than thosepreviously used.

One of the objects of the present invention is to provide a method ofand means for effectually decolorizing and/or stabilizing distillatepetroleum products, particularly those of A. P. I. gravity higher than37 degrees, with respect to color, gum formation and odor in thepresence of water.

Another object of the invention is to provide agents or compoundseffective in removing initial or recurrent discoloration of distillatepetroleum products and for stabilizing the same as to color, odor andthe formation of gum, which agents or thoroughly mixed with thedistillate to be treated,

resulting solution is then added to the distillate acteristic materiallyaffects the commercial valuecompounds are more soluble in thedistillates and less soluble in water than those previously used.

Among the compounds in the nature of negative oxidation catalysts thatwe have discovered are efiectiveas decolorizers and stabilizers of distillate petroleum products with respect to color, gum formation andodor, whether in the presence of water or not, are the alkyl substitutedhydroxybenzenes, especially methyl, ethyl, propyl' and butyl pyrogallol.These compounds are formed preferably by substituting alkyl groups forsome of the hydrogens in pyrogallol, and are substantially insoluble inwater but readily soluble in distillate petroleum products. For example,butyl pyrogallol is only thirty times more soluble in water than inkerosene, whereas pyrogallol is thirty thousand times more soluble inwater than in kerosene.

A relatively minute amount, preferably less than 0.01% of the agent'orcompound may be although it will be understood that the distillate 'maybe percolated through a mass of the compound, if desired. Preferably,however, the compound is first dissolved in a. suitable solvent which ismiscible with the distillate, such as an allphatic alcohol, particularlyisopropyl alcohol, in the proportion of one p'artof the compound toapproximately ten parts of the solvent. The

such an extent that thedistillate contains less than 0.01% of thecompound. This method usually results in the compound being distributedthroughout and dissolved in the distillate more readily than if it wereadded directly thereto.

The results of the following tests will illustrate the effectiveness ofthe treatment of distillate petroleum products in accordance with ourinvention.

95 A sample of kerosene which had developed a color of minds 15, asmeasured by the Saybolt chromometer, was treated with one part of propylpyrogallol to 25,000 partsof oil. After standing for one day the colorof the treated oil improved to plus 10, an improvement of 25 points incolor. I

Samples of gasoline were treated with equal molecular proportions .ofpyrogallol and butyl pyrogallol (one part of pyrogallol to 72,600 partsof oil and one part of butyl pyrogallol to 50,000 parts of oil) Thegasolines so treated were stored for six months, and the color by theSaybolt. chromometer and the gum content, by evaporation of 100 cubiccentimeters in a porcelain dish were then determined. The results ofthese tests were as follows:

These results show that when pyrogallol and butyl pyrogallol are used inequal molecular quantities, the butyl pyrogallol isthe more effectivestabilizer and decolorizer, because of its greater solubility in thedistillate.

While we have thus specifically described our invention, variousmodifications thereof may suggest themselves to those skilled in theart, and it therefore is our intention that the invention be limitedonly by the scope of the appended claims. 1

We claim: 7 7

1. A low boiling normally light colored distillate petroleum product ofthe class of gasoline or kerosene which normally tendsto deteriorate byoxidation, as evidenced by the formation of color or gum therein duringstorage, having add ed thereto a small amount of a butyl substitutedpyrogallol 'sufllcient substantially to retard the aforesaiddeterioration, the butyl group being substituted for hydrogen of thebenzene nucleus.

2. The method of stabilizing the characteristics of a low boilingnormally light colored petroleum distillate product of the class ofgasoline or kerosene that normally tends to deteriorate by oxidation, asevidenced by the-formation of color or gum therein during storage, whichcomprises adding thereto, prior to substantial deterioration asaforesaid, a small proportion of a butyl substituted pyrogallolsufiicient substantially to retard the aforesaid deterioration, thebutyl group being substituted for hydrogen of the benzene nucleus.

3; The method of decolorizing a normally light colored low boilingpetroleum distillate product of the class of gasoline or kerosene whichhas become discolored by spontaneous color formation during storage,which comprises adding to said discolored product a small proportion ofa butyl substituted pyrogallol sufficient to effect

